diff -r 110e070b77a7 -r b8ec7b2f5ed0 src/sim/serialize.hh
--- a/src/sim/serialize.hh	Mon Sep 29 11:38:01 2014 +0100
+++ b/src/sim/serialize.hh	Mon Sep 29 11:38:15 2014 +0100
@@ -43,6 +43,7 @@
 #include <map>
 #include <vector>
 
+#include "base/bitunion.hh"
 #include "base/types.hh"
 
 class IniFile;
@@ -63,14 +64,37 @@
 template <class T>
 void paramOut(std::ostream &os, const std::string &name, const T &param);
 
+template <typename DataType, typename BitUnion>
+void paramOut(std::ostream &os, const std::string &name,
+              const BitfieldBackend::BitUnionOperators<DataType, BitUnion> &p)
+{
+    paramOut(os, name, p.__data);
+}
+
 template <class T>
 void paramIn(Checkpoint *cp, const std::string &section,
              const std::string &name, T &param);
 
+template <typename DataType, typename BitUnion>
+void paramIn(Checkpoint *cp, const std::string &section,
+             const std::string &name,
+             BitfieldBackend::BitUnionOperators<DataType, BitUnion> &p)
+{
+    paramIn(cp, section, name, p.__data);
+}
+
 template <class T>
 bool optParamIn(Checkpoint *cp, const std::string &section,
              const std::string &name, T &param);
 
+template <typename DataType, typename BitUnion>
+bool optParamIn(Checkpoint *cp, const std::string &section,
+                const std::string &name,
+                BitfieldBackend::BitUnionOperators<DataType, BitUnion> &p)
+{
+    return optParamIn(cp, section, name, p.__data);
+}
+
 template <class T>
 void arrayParamOut(std::ostream &os, const std::string &name,
                    const T *param, unsigned size);